argument47 [kb9.11]第六次作业

qiuzirumengUID: 199691

TOPIC: ARGUMENT47 - Scientists studying historical weather patterns have discovered that in the mid-sixth century, Earth suddenly became significantly cooler. Although few historical records survive from that time, some accounts found both in Asia and Europe mention a dimming of the sun and extremely cold temperatures. Either a huge volcanic eruption or a large meteorite colliding with Earth could have created a large dust cloud throughout Earth's atmosphere that would have been capable of blocking enough sunlight to lower global temperatures significantly. A large meteorite collision, however, would probably create a sudden bright flash of light, and no extant historical records of the time mention such a flash. Some surviving Asian historical records of the time, however, mention a loud boom that would be consistent with a volcanic eruption. Therefore, the cooling was probably caused by a volcanic eruption.
WORDS: 263          TIME: 00:30:00          DATE: 2007-8-23 23:28:27

According to the artical, the author make the conclusion that the significant sudden cooling on earth attributes to a volcanic erution rather than a meteorite coliding with earth. This argument is problematic i several respects, rendering the argument unconvincing as it stands.

A thresh problem of this argument is it bases on the assumption that there are only two possible explanations of sudden cooling on  the earth. In fact, it is entirely possible that alterative reasons exists. Perhaps the sudden change on temperature is just because the sun has fallen into a nonactive period, which in turn lead to the lower temperature on earth. Without considering and ruling out other reasons, the argument fails to convince us that the cooling is caused volcanicc eruption rather than colision with meteorite.

Even if there are indeed just these two alteratives that explane the sudden cooling on earth, the author provide no evidence to exlude the possiblity of colliding with meteorite. Only by mentioning that no extant historical records of the flash during athe collision can not preclude this possibility at all. Especially considering that the collison happened in the mid-six century, it is entirely possible that the records indeed was written but not kept well or even lost after a long period. Lacking direct evidence to exclude the possiblity of collison, the author's conclusion is not reliable as it stands.

As the author mentions a loud boom in Asian historical recors to support his/her conclusion. However, the author fails to provide any direct evidence to substanticate that this loud boom have relations with the volcanicc eruption. It is likely that the loud boom is just the collison of meteorite with earth. Or perhaps this loud boom just an independent occurence which has nothing to do with the eruption mentioned in the argument. Failing to estabish a causal-and-effect relationship between loud boom and vocalnicc eruption, this argument far from suffficient to justify its conclusion.

To sum up, this argument fails to estabish a direct relationship between sudden cooling on earth and vocalnicc eruption, as well as exclude the possiblity the alterative of meterorite collisions. To strengthen the conclusion, the author has to provide some direct evidence to support that vocalnicc eruption is the only possible reason that lead to sudden cooling of temperature on earth.